1. Field of the Invention
The invention concerns a machine for electrostatic spraying of coating products onto objects such as automobile vehicle bodies.
2. Description of the Prior Art
On a production line the bodies are moved by a conveyor and the coating product spraying machine comprises a gantry supporting a horizontal beam perpendicular to the path of the bodies and this beam carries one or more coating product sprayers, which are of the rotary type, for example. These machines, which are sometimes referred to as overhead machines, are of primary importance for the coating of the objects to be painted, especially if the objects have many substantially horizontal surfaces like the trunk, the roof and the hood of an automobile vehicle body.
The complexity of these machines stems mainly from the feeding of the coating product and air to the sprayers when these can move over large distances. Long hoses are required and the location of control units in restricted spaces is often difficult. Additionally, the sprayers being at the high voltage, it is necessary to insulate them from any object at ground potential. Prior art electrostatic spraying machines usually include three sprayers carried by a metal beam and fed with coating product from one or more coating product change units located near the machine and supplied with voltage from one or more voltage increaser units (high-tension units) also located near the machine.